The present invention relates to a cable closure, particularly to an aerial cable splice case, more particularly to a ready access splice case, especially for the telecommunications industry.
Closures are required around cables, to provide environmental protection, particularly against water and other contaminants and against insect or animal damage. Such closures are especially necessary around cable splices where one cable is terminated, where one cable is joined to one or more other cables, or where drop wires (for example to individual subscribers in the case of a telecommunications cable) are joined to a cable. The level of environmental protection required will depend on the type of cable and its location. In general, buried cables require a more complete seal than aerial cables because buried cables may become immersed in water. Also, pressurised cables require a pressure resistant seal, whereas unpressurised cables may not. Some aerial closures may offer protection merely against excessive sunlight, rain or insects and animals, but be able to pass air and may have provision for water drainage should any water accumulate inside. In each of these cases, however, a closure may be said to be provided that offers some sort of environmental seal.
Many designs of cable closure have been proposed, and the following are given as examples.
U.S. Pat. No. 3,337,681 (Smith) discloses a cylindrical cable splice case comprising two rigid half-shells that are bolted together through longitudinally extending flanges thereof. An end seal is provided at each end of the resulting cylinder. The end seals have holes through which the outgoing cables pass.
U.S. Pat. No. 3,711,632 (Ghirardi) discloses an end fitting for use with a flexible axially slit tube for housing a plurality of electrical leads. The end fitting includes a pair of sections of generally circular cross-sectional shape which are hinged along their adjacent side edges and which are foldable about the hinges to a closed position.
U.S. Pat. No. 4,421,945 (Moisson) discloses a re-enterable assembly for forming a cable splice case, which comprises a split tube, each half of which rests on support end pieces through which ingoing and outgoing cables pass. The halves of the split tube have projections for mutual interengagement. The end pieces and split tube are surrounded by a heat-shrinkable sleeve.
U.S. Pat. No. 3,836,694 (Kapell) discloses a re-enterable cable splice case comprising a two-part housing. A removable layer of water restricting material is provided around the splice within the housing
U.S. Pat. No. 3,846,575 (Troy) discloses a ready access cable closure which comprises a base that includes upstanding ends through which the cables pass. A cover is provided that, together with the base, forms a sealed housing. The cover, U-shaped in cross-section, is installed by positioning it over the base in a direction perpendicular to the length of the splice. Drop wires can leave the splice through holes in the base.
U.S. Pat. No. 4,519,014 (Skorran) discloses a ready access splice closure, having end pieces that are slotted over the cables either side of the splice. A tube is positioned over the splice and over the end pieces.
U.S. Pat. No. 4,581,265 (Follette) discloses a flexible wraparound closure for enclosing a cable splice, and which can be easily reopened. The closure comprises a flexible water-resistant sheet, opposite edges of which can be brought together around the splice and held together for example by a zipper. The sheet, together with any internal liner, can be held in the open position by means of a holding collar that can be rotated into a position above the splice. This allows work to be carried out on the splice. End seals between the wrapped sheet and the cables may comprise a gel material.
U.S. Pat. No. 3,701,835 (Eisele et al.) disclose a cable terminal unit providing a limited access cable compartment within which electrical leads from terminal blocks may be spliced into a telephone cable. The unit is generally cylindrical, a part of the cylindrical surface being hinged with respect to the remainder so that the compartment can be exposed.